Here are some facts are about the climate that are part of the consensus:

The planet has warmed about at about 0.7 degrees centigrade over the past century. Who is denying that? It ain’t me.

Carbon dioxide has been demonstrated to be a greenhouse gas. Who is denying that? It ain’t me.

Our basic climate understanding (i.e. the models) indicate that if we doubled CO2 from pre-industrial levels (which were close to 280 ppm, we are very near 400 right now) then temperatures, knowing what we know about carbon dioxide, should double. The 0.7 increase does seem to be in line with that (mostly, I have seen, even among alarmists, “concern” that this number ought to have been larger). Hence if we continue to double CO2 over the next century, the planet will warm by 1 degree centigrade, all else equal. Who is denying that? It ain’t me.

But that’s about where the real scientific consensus ends, and certainly where the major disagreements begin. Because as others have pointed out countless times, only to be slandered as anti-science lunatics, in order for us to need to roll back industrial civilization, in order for us to rapidly impose decarbonization, in order for us to retreat to the pre-civilization gift economies that so many folks seem to long for, one would have to demonstrate that:

When CO2 concentrations increase, the planet will warm by much more than the basic greenhouse gas theory indicates. So, the climate models believe that there are positive feedback loops which will amplify the impacts of 1 degree of warming into something closer to 6 degrees of warming. There is absolutely no settled science here.

Call this step 1a: we have to assume that even with our limited knowledge that we have any capability at all of modeling something as complex as climate – with really only 100+ years of data using measurements (even if all of those measurements are correct) and at best another 1000 years or so using temperature proxies (assuming no problems with those things). We’ve discussed this in the past in terms of how it compares to macroeconometric modeling. Let’s just say this is little more than a guessing game.

Then we are going to have to assume that all of the warming that we have observed (and model) comes from humans. Of course it is almost surely true that humans are the reason why CO2 concentrations are higher today (there are some legitimate folks who do not think this is necessarily true, but ignore them). And by extension we’d have to argue that all of the potential future catastrophically bad warming will be solely because of human activities.

Then we have to know, with some degree of certainty, exactly what will happen to the Earth as it warms. And we will have to argue that as this happens over the course of decades or perhaps a century-long time scale that the challenges will prove un-over-comeable. So, we’d have to draw linkages between warmer climate to rising seas (easy enough), expanding malarial ranges (almost as easy), changes in farm productivity (sort of easy) and so on.

But not only that, we have to know with some degree of certainty that these changes caused by warming, are not only tough to deal with, but are catastrophically bad.

But not only that, we have to know with more than some degree of certainty that rolling back industrial civilization is the way to best deal with (5).

All of this is assuming of course that in nowhere along the way is anyone motivated by political or ideological reasons either on the science or policy side, so that we actually could be having a serious entertainment of the inquiry. But I’m a 9 foot tall Nobel Prize winner if that is true. I keep coming back to this thought.

I am skipping many steps, but this is neither a climate site nor an environmental economics site. The reason for today’s post is not all of that, it has been said by smarter and more thoughtful people than me many times and they still have been dismissed as cooks, cranks, anti-science deniers. One need not disagree at all with what the scientists truly understand yet vigorously reject the conclusions drawn by folks who hold themselves as the paragons of science, truth and reason. Here is the latest illustration. One of the most serious potential climate threats is the expansion of malaria around the globe. Already a horrific threat (after a conference we held, which included several scientists, I reported on the expected costs here), a warmer planet is expected to make this problem worse.

No one I know of denies any of this. But few people I know realize that it doesn’t follow that we eliminate industrial civilization to fix the problem, assuming it is going to manifest. Here is a new paper from a UK scientific journal called the Lancet:

Our findings show that the malaria mortality burden is larger than previously estimated, especially in adults. There has been a rapid decrease in malaria mortality in Africa because of the scaling up of control activities supported by international donors.

In other words, in just a six year period, the number of malaria deaths around the world decreased from 1.8 million to 1.2 million. You read that correctly. Malaria deaths fell by roughly a third. And remember folks, not only did these deaths fall by a third, they fell by a third during a time when the consensus agrees that global temperatures are at record highs (at least during the instrumental record) and showed no signs of tapering off to lower levels. In other words, in the presence of global warming the malaria problem has been considerably improved. Note that this does not mean that the warmer planet did not expand the population at risk for exposure to malaria. That may or may not be an interesting fact. But it does mean that something else, aside from ending industrial civilization as we know it, had a hand in reducing global malaria death, and those trends are not just gains in rich places, the biggest gains have again been happily in Africa – which continues (it appears) its run of a decade of very impressive economic growth.

The point of all of this? One of the most fundamental reasons for being alarmed about a warming planet, disease spread, has no business at all (in a real model of human behavior) being included among the unique problems of global warming. Or if it does, then somehow someone ought to model what has just happened in the last decade around the globe – because that sure ain’t what you see in the IPCC’s 4th assessment report, and I’ll bet more than a cup of coffee that it ain’t what you’ll see in the forthcoming 5th assessment report. And the fact remains is that this sort of observation and understanding need not be limited to malaria spread. The impact of the consensus/agreed upon problems that are likely to be caused by a warming planet may not be large enough as compared to our human ingenuity at dealing with it.

I’ve told my students for years that regardless of the temperature record or CO2 concentrations (which at best are markers for potential damage) I’ll convert myself to a “true believer” when I see measures of human well-being obviously suffering. Yet despite the warming planet, and continued expectation of warming, infant mortality rates continue to fall, life expectancy continues to increase, crop-yields (though their rate of increase has slowed – sort of like how we think of government budget “cuts”) continue to increase, air pollution continues to fall (including ozone) and mortality related to factors like heat seems to be on the decline too (uh oh, that link was from a “free-market” energy blog, I am sure the Kochs paid the guy to make all of that up).

So no one I know who is serious denies anything about what the consensus is about global warming. But then again I know of virtually no one in the alarmist community who recognizes anything about what I’ve written here today. Maybe I don’t go to enough cocktail parties. Sure. But who, I ask, really is the denier here?

Great post, WC. I know you did not mean to provide an exhaustive list of questions, but here’s one I would like the answer to: how come CO2 is just 400 ppm? After millions of years of the animal kingdom exhaling it, why is it not 400,000 ppm? Well, the plant kingdom breathes it in. I read somewhere that plants grow more rapidly in a CO2 rich environment; true, plants like corn also grow better when there is less competition from weeds, and plenty of water, fertile soil, and sunshine. You would think the CO2 phobes would be all for GM seeds. Also, if you are talking about malaria, you would want to drain the swamps, too.

About fifteen years ago, back when Exxon was not Exxon-Mobil (Lee Raymond days), I think even they conceded the 0.7 degrees C number, and I am not going to argue about whether Lee Raymond thought it was getting warmer over his lifetime. Every person who grew up east of the Mississipi thinks sledding was better during the Eisenhower years.

I will agree to that number as long as someone qualifies it by saying, plus or minus a degree. If you go back to the days of commercial airports, say, eighty years ago, then the data get better for airports, but still not as precise as a tenth of a degree C.

So plug in any of this data, which is at best precise to a single degree without adjusting for other variables like altitude and what was happening in Sumatra even last year, and you can produce any result you like, and that is not science, it is at best a hunch, all of what is connected to CO2 as is rabbit reproductivity rates in selected Texas counties. I guess that makes me a general denier of BS.

[…] a warmer planet will cause problems because disease vectors will spread, most notably, malaria (see here by the way) what they do is set the initial conditions of their climate model. Then they simulate what will […]

[…] by the wizards in the IPCC to estimate just how severe the costs of global warming are going to be. Remember, one of the major costs was supposed to be the serious negative impact of expanding malaria ranges in Africa. Sciency […]